I'm making a marble Monopoly board. Each space on the board will be a 3" x 1.5" piece of marble, purchased as small tiles from Home Depot, then cut to size using a budget tile wet saw. I will etch the ingots on a laser cutter. (Tests have been great.) The saw cuts the tile ok but the cut dimensions aren't exact enough for my needs. I want to be able to sand/grind the edges of the ingots, both to correct any erratic size variances or angles, as well as smooth out the edges. Suggestions?
Marble is easy - this is not at all dissimilar to finely fitting marble tiles, and marble being a relatively soft rock, you can wet-sand it, or use a silicon-carbide block from the tile section at the home improvement store to dress it to precise size. The block will last longer, but is quite coarse - wet/dry sandpaper can be had in a number of different grades from very coarse to very fine.
Without knowing for sure, I also wonder if you are merely up against a "budget tile saw" or if you are forcing the cuts rather than letting the saw cut at a speed it's happy with. Most diamond-blade tile saws (particularly wet ones) make quite good cuts, when run properly, unless the whole thing is really shoddy.